Catalytic activity of phenyl substituted cyclopentadienyl neodymium complexes in the ethylene oligomerization process

New mono-and bis-cyclopentadienyl neodymium ate-complexes, bearing phenyl-substituents in the cyclopentadienyl ring, have been synthesized: KNdCp'Cl-3(thf)(x) (Cp' = 1,3-Ph2C5H3 (1), 1,2,4-Ph3C5H2 (2)) and KNdCp'Cl-2(2)(thf)(x) (Cp' - 1,3-Ph2C5H3 (3), 1,2,4-Ph3C5H2 (4), 1,2-Me-2-4-PhC5H2 (5), 1,2-Ph-2-4-(4-MeO-C6H4)C5H2 (6)). Their catalytic activity has been studied in ethylene oligomerization process in the presence of Bu2Mg as a chain transfer reagent with the Nd:Mg molar ratios being of 1:20, 1:40 or 1:80. Complex 4 exhibits catalytic activity close to the activity of the known complex [(C5Me5)(2)NdCl2Li(OEt2) 2] (7). The complex 6 has demonstrated the best catalytic activity among all studied complexes. Using selected complexes 2, 4 and 6 as pre-catalysts, terminal iodo-functionalized oligoethylenes have been prepared. Obtained iodooligoethylenes have been studied by H-1 NMR technique and MALDI mass-spectrometry with preliminary derivatization, demonstrating 70-90% of functionalization. Crystal structures of ate-complexes [{(1,2,4-Ph3C5H2)Nd(thf)}(2)Cl5K](2)(toluene)(4) (2a), [(1,2,4-Ph3C5H2)(2)NdCl2K(thf)(0.53)(1,4-dioxane)(1.47)](2)(dioxane) (4a) and {[{1,2-Ph-2-4-(4-MeO-C6H4)C5H2}(2)NdCl2K](2)(1,4-dioxane)}(toluene)(4) have been studied by the single crystal X-ray diffraction. (C) 2016 Elsevier B.V. All rights reserved.